Release compositions are used, for example, to coat papers or films that are used as release backing sheets overlying the pressure sensitive adhesive layer used in pressure sensitive adhesive (PSA) products such as labels, decals, tapes, etc. The PSA adheres to the release coated surface of the release backing sheet sufficiently to enable the pressure sensitive products to be handled prior to use. When such products are used, the release backing sheet is pulled off and discarded. The exposed PSA is pressed onto a surface where the pressure sensitive product is to be placed.
The PSA layer may be applied to the release liner as a coating by any conventional technique known in the coating art such as roller coating, curtain coating, brushing, spraying, reverse roll coating, doctor knife, dipping, die coating, offset gravure techniques, etc. In the manufacture of adhesive coated articles, including labels, using the curtain coating method, there is often the problem of air entrapment between the adhesive coating and the silicone release surface of the release liner. The problem may manifest itself as hazing and/or bubbles in the adhesive layer. This problem is particularly troublesome when the adhesive article or label facestock and the adhesive layer are both clear.
Clear polymeric labels are increasingly desired, since they provide a no-label look to decorated glass and plastic containers. Paper labels block the visibility of the container and/or the contents in the container. Clear labels enhance the visual aesthetics of the container, and therefore the products, and are growing much faster than paper labels in the package decoration market as consumer product companies are continuously trying to upgrade the appearance of their products on store shelves.
There is a need, therefore, for improved methods of forming clear adhesive layers, particularly for adhesive layers to be used in clear labels. More specifically, there is a need for an improved silicone release liner for use in adhesive coating operations such as curtain coating.